mccornack



H. MccoRNAcK 'P QLsA'ToRgVFoR MILKING MACHINES Filed'Aug. 12. 1920 5Sheets-sheet 1 A TTOHNE VS Aug. 28, 1928. 1,682,392

. H. MocoRNAcK PULSATOR FOR MILKING MACHINES Filed Aug. 12. 1920 .i5Sheets-Sheet 2 i; L INVENTOH a 8l I I* A ITU/MIE YS 5 snets-sneet 3 H.MCCORNACK PULSATOR FOR MILKING MACHINES Filed Aug. l2, 1920 t lti-I4Aug. 2s, 192s. 1,682,392 H. MCCORNACK PULSATOR FOR MILKING MACHINESFiled Aug. 12. 1920 5 Sheets-Sheet 4 A TTOR/VEYS Aug. 2s, 192s.`1,e82,392

H. MCCORNACK PULSATOR FOR MLLKING MACHINES Filed Aug. 12. 1920 5:sheets-Sheetl 5 /N VEN 70H A TTUHNE YS Patented Aug. 28, 1928.

UNITED STATES l 1,682,392 PATENT OFFICE.

HERBERT MCCORNACX, OF GLEN RIDGE, NEW JERSEY.

PULSATOB FOB HILKING MACHINES.

Application mea August 12, 1920. serial m. 403,013.

This invention relates to improvements in milkingmachines and moreparticularly to pulsators therefor of the ty e which operate toalternately cut off an .supply va cu um or pressure to the teat cups ofmllkmg ap aratus.

he general purpose of the invention is to provide pulsator mechanismwhlch 1s positivel and efficient in its operat1on ,vand which is simplein its construction and 1n the manufacture and assemblage of its severalparts. It is also a purpose of the inventlon to so construct theapparatus that the several parts thereof may be removed quickly andreadily when it isdesired to have access thereto for any reason, as forexample, for

, cleaning or repairing. Further, the inven- -tion has for its object toprovide an apparatus of this type which is durable in use, and in whichleakage from wear is prevented.

In the accompanying drawings, forming a part of this specification:-

Figure 1 is a plan View of a receptacle cover having mounted thereonpulsator mechanism constructed according to and embodying my invention,one set of teat cups heilig shown connected thereto;

Figure 2 is a front elevation thereof;

Figure 3 is a sectional view taken on the line III-III of Figure 1;

Figure 4 is a sectlonal view taken on the line IV-IV of Figure 1;

Figure 5 is a view similar to Figure 4 but showing the parts of themechanism as occupying different positions;

Figure 6 is a detail sectional View showing a slightly modifiedconstruction;

Figure 7 is a plan view of the piston;

Figure 8 is a bottom view of the reversing valve;

Figure 9 is a sectional view taken on the line IX-IX of Figure 8;

Figure 10 is a bottom view of the valve actuating plunger and itsassociated parts;

Figure 11 is a detail view of a portion of the mechanism;

Figures 12 and 13 are det-ail sectional views illustrating two differentpositions of the` milk cock.

Figure 14 is a plan view showing a slightly modified construction;

Figure 15 is a rear elevational view thereof, and

Figure 16 is a sectional view taken on the line XVI-XVI of Figure 14.

Referring to Figures 1 to 13 of the drawings, the milk receptaclecomprises a pail 1 and a cover or lid 2, provided with a rubber gasket2, within which is embedded a wire 2f which prevents the gasket fromstretchlng or being stripped off. Mounted upon the cover is a nipple 3adapted to be connected by tubing or piping to a source of vacuum. Atits inner end the nipple 3 communicates with a port 4, which in turncommumcates with a chamber 5 provided at its lower end with a suctionport 7 leading to the interior of the milk pail 1. The upper end of thechamber 5 is closed by a cap 8, having a threaded portion 9 engaging athreaded opening 10 formed in the cover 2. In order to provide afluid-tight joint,

the cap is provided with a beveled surface 8a whereby the suction withinthe chamber 5,

during the milking operation, will cause the check valve 11 to be raisedto open the port 7, thus placing the interior of the` ail 1 incommunication with the/vacuum. it its up# l per end the check valve 11is provided with an. annular groove 11HL to permit it to be gripped bythe fingers when it is desired to lift the valve from the chamber 5.Formed 1n the cover 2, and communicating with the interior of the pail1, is a valve chamber 13 provided with ports 14, 14 communicating withnipples 15, 15. Within the valve chamber 13 -is a rotatable hollow valveor milk cock 1'6 having a port 17 adapted to be moved into register witheither one (Figure 12) or both (Figure 13) of the ports 14, 14, wherebythe same will be laced in communication with the interior o the pail1,or to be moved out of register with both of the ports to close thesame.

The pulsator mechanism, which is mounted upon the cover 2, comprises acylinder consisting of a central body portion 18, preferably formedintegrally with the cover 2, and removable caps 19, 20, constituting theend which may be drawn in a press or otherwise formed, are normally heldin position with their free edges engaging the end walls of the bodyportion 18 of the cylinder, in a portions of the cylinder. The caps 19,2O

` (Figure 1.) The nipplesY 15 and 27, of each set of nipp1es,.areadapted to be connected by flexible pipes 28, 29 to the two manifolds30, 31 of a claw and set of teat cups. As shown, the teat cups are ofthe double chamber type, having a rigid outer casing 32, and an innerflexible lining or ination 33. Thev inflations are in communication withthe manifolds 30, while the space between the outer casing and theinflation of each of the teat cups is inI communication with themanifold 31. When the apparatus lis in use, there will be a continuoussuction from the milk pail 1, through the port 14,l nipple 15, pipe 28and manifold 30, to the interiors 'of the infiations 33, and this vacuumwill draw the milk from the cow and carry it to the milk pail 1. Thevacuum within the spaces between the outer casings andthe iniations willbe pulsated by the pulsator valve mechanism, hereinafter described, insuch amanner that atmospheric pressure will be admitted tosuch spacesalternately with the application of vacuum thereto. This alteration ofatmospheric pressure and vacuum causes the teat cup lining to alter--`nately extend, so as to permit the milk to flow, and to collapse uponthe teat so as to support and relieve the -same thereby preventingcongestion in the teat and permitting the mllking operation to becarried on in a normal manner.

It will of course be understood that the particular form of teat cupconstitutes lno part of the present invention and that anyl suitabletype of cup maybe used in connection with the pulsator herein described.

Mounted to reciprocate within the cylinder 18, 19, 20, is a piston 34having a cen-l trally disposed recess 35 formed in its under surface andconstituting a valveto connect the suction port 22 alternatelywith theports 2l and 23, as the piston reciprocates. The upper, central portionof the piston is cut away, as shown, and passages 36, 36 are provided,which extend through the reduced body portion of the piston,communicating at their upper ends with the interior of the cylinder andat their 'lower end with recesses 37, 37v

formed in the under surface of the piston at either side of the recess35. As the piston is moved to cause the valve 35 to connect the suctionport 22 with either one of the ports 21 and 23, the other one of' theseports will be opened to atmospheric pressure through a recess 37,passage 36, the interior of the cylinder and an opening 38 formed in thewall of the cylinder, which is preferably provided with an air-filter 39of any suitable construction for the purpose of preventing dust or anyforeign matter from entering the pulsator mechanism and causing damae orwear of the moving parts thereof. ne form of filter for such purpose isshown in Figure 3 as comprisin a tubular body portion filled with asuita le filtering material, sch as mineral wool, which is retained inposition by wire netting or the like, secured to the body portion at theends thereof.

The piston 34 is provided at each end with a leather cu washer 40 heldin position by a screw 41 w ich engages a threaded recess 42 formed inthe end of the iston. The ends of the piston are reduced s ghtly `topermit the anges of the leather cups 40 to e received between the istonand the walls of the cylinder and t e flanges are constantly ressedoutwardly against the cylinder wa ls, to form a tight jointtherewith, bresilient tension rings 43 preferably ormed of cork or cork composltionand mounted within annular grooves 44 formed in the reduced ends of thepiston. The cork rings 43 do not engage the inner surface of the grooves44 and are free to float laterally in all directions to a limitedextent, thus maintaining an even pressure upon the flanges of `the cupsat all points.

thereof. The rings 43 are split transversely tol enable them to bepositioned within the grooves 44, and whenso positioned the `ends of therings abut, thus forming, in eli'ect, a

solid ring. In place of the cork rings 43, coiled springs 45 may beutilized, if desired, to exert the required pressure upon the cupflanges, as shown in Figure 6.

The screws 41 have longitudinal passages 46, extendin therethrough,which communicate with t e ends of the cylinder and with spaces 47formed withinthe piston between the inner ends of the screws 41 and theinnerv walls ofthe recesses 42. -The spaces 47 are in turn connected bypassages 48, 49 (Fig-A ure 7) with ports 50, 51 formed' in the planellll surface 52 at the central cut away'portion v ofthe piston.Intermediate the ports 50 v andv 51, the plane surface .or valve seat 52is providedwith a third port 53, from which a passage 54 leads to anelongated opening 55 formed in the surface of the piston an registering,at all positions of the piston,

with the end of a passage 56 formed in the cover 2 and communicatin withthe cham-l ber 5, (see Figure 3). he flowl of air through the assage 56is controlled b a regulating va ve 57 adjustably mounte in an opening inthe cover '2.

The plane surface 52 of the piston 34 constitutes a valve seat for areversing valve 58 suction to w ich that end of the cylinder is ment obe reversed and the which is reciprocatingl` mounted thereon betweenguides 59, 59. he valve 58, (Figures 8 and 9) is provided in its undersurface with a centrally ositioned recess 60 adapted, as the valve 1sactuated, to conmect the port 53 alternately with one of the ports 50and 51, whereby first one and then the other of these orts will beplaced in communication with) the vacuum. When either one of the ports50 and 51 is in communication with the ort 53, the other one thereofwill be opened) to atmospheric pressure as it will be in register withone or the other` of the recesses 61 formed in the ends of the valve 58.It will thus be seen that at the end positions of the valve 58, one endof the cylinder will have the pressure therein reduced by itscommunication with the source of vacuum and the other end thereof willbe opened to atmospheric ressure, as a result of which the piston willbe caused to travel within the cylinder. Upon the shifting of thereversing valve 58 to its other position, the pressure conditions willpiston will be caused to travel in the opposlte direction. At eachreciprocation of the piston 34, the cap at the end of the cylindertoward which the piston is traveling will be held firmly seated againstthe central ortion of the cylinder by the subjected, and the cap at theopposite end of the cylinder will be held in position by the drag causedby the friction between the cup leather 40 and the inner wall of thecup. lVhen the apparatus is not being operated, both ca s will beretained in ,positionv by reason of t e friction between their walls andthe cup leathers of the piston.

Durinor the operation of the piston the valve at the underside thereofis kept pressed firmly upon its seat by the weig t of. the piston, andalso by the atmospheric pressure acting on the upper side thereof andthe suction to which the recess 35. of the valve on the undersidethereof is subjected, therebyipreventin any leakagefbetween the movingparts. wing to the fact that the caps 19, 2O at the ends of the cylinderare movable with respect to the body portion 18 thereof, they will becarried down by the piston, as the latter, and the valve seat upon whichit moves, wear and will alwaysV remain concentric with the piston. Asthe piston is constantly pressed downwardly, as aboveset forth, and asthe ports controlled thereby are below the axis'of the cylinder, thepiston will be pressed firmly upon thevalve seat, as the co-acting partswear, thus preventing any leakage therebetween.

The length of the `reversing valve 58 is less than t "e length of thecut away portion of the iston 34a in order to permit movei) they valverelatively to its seat, whereby it may be shifted a suicient distance toeffect the alternate connecting .of the ports 50 and 51 with the port53, as above described. At its center, the valve 58 is provided with anupwardly extending wedge-shaped portion 62 (Figures 4, 5 'fand 9), withwhich co-acts the wedge-shaped head 63 of a spring pressed plunger 64 orvalve shipper reciproeatingly mounted within a plug 65 which fits in anopening in the top of the central, bod portion 18 of the cylinder, andis remova ly held in place by suitable means such as the set screw 65,(Figure 11). At either end of the head 63, the plunger is provided withrollers 66 which lengage guideways 67 formed in the plug 65 and serve tomaintain the head 63 properly positioned with respect to thewedge-shaped portion 62 of the Valve 58. The plunger 64 serves to shiftthe reversing valve 58 from one of its operative posit-ions to the otherthereof, and to prevent such shifting movement from being madeprematurely. When the valve 58 is in one of its operative positions, asshown for example in Figure 5, one end of the valve will be inengagement with the corresponding end Wall of the cut away portion ofthe piston 34, the recess 60 will be n'position to connect port 53 withone or the other of the ports -50 and 51, and the other one of these twoports will be subjected lto atmosphericpressure through one of therecesses 61. The valve 58 will be securely held against movement uponits seat 52 by the plungerl 64, the head 63 of which will be inengagement with Athe wedge shaped porvtion 62 of the valve. As the istonmoves from left to right, as seen in 4igure '5, the valve 58 will bemoved therewith, but it will still be held in its operative position bythe vplunger 64, which will be forced gradually upwards by the co-actionof the inclined faces of the wedge-shaped members. The Valve 58 willremain in its position upon the valve seat 52 until it has been movedsuiiciently to cause the edges ofthe wedgeshaped'members to register,but the instant the' edge'of the wedge-shaped portion 62 of the valve 58is carried past the edge of the -wedge-shaped head 63 of the plunger 64,the

latter will be forced downward by the spring and the valve 58 will beinstantly shifted upon its seat 52 to its other operative position inwhich the port wheh was in communication with the port 53 will now beexposed to atmospheric pressure, and the port which was formerly exposedto the atmosphere will now be in communication ,with the port 53.

The cover 2 is provided with a suitable handle 68 which is removablysecured thereto by bolts 69, whereby the handle may be readily removedwhen it is desired to ave access to the `pulsator mechanism for anyreason, such as ele'aning'or repairing. When the handle 68 is inposition, the downwardly the set of nipples 15, 27 at the left in Figure1, are connected to a set of teat cups 1n the same manner in which theset of nipples `at the richt are shown connected, the vacnum producedwithin the chamber 5 will cause the valve 1l to be lifted off of itsseat, thereby subjecting the interior of the pail to vacuum. As thehollow valve 16 will be in position to eii'ect communication between theinside of the pail and the nipples l5, of both sets of nipples, theinflations 33 of the teat cups to which the nipples 15 are connected bythe tubing 28, will be constantly subjected to the vacuum and hence themilk will be drawn to the pail. Assuming the movable parts of thepulsator mechamsm to be in the positions shown in Figure 5, the valve 35at the under side of the l piston 34 will be in position to place port21 in communication with port 22, and port 23 will be uncovered. As port22 communicates with the chamber 5 through the passage 25, the same willbe subjected to the action of the vacuum', and consequently the spacesbetween the outer casings 32 and the inner linings 33 of the teat cups,which are connected to the nipple 27 of the left hand set of nipples,will be subjected to the vacuum. At the same time the correspondingouter chambers of the teat cups which are connected to thenip le 27 ofthe right hand seto nipples, will e subjected to atmospheric ressure asthe port 23, to which the right hand nipple 27 is connected, is open tothe atmosphere through recess 37, passage 36, upper portion of cylinder,and theopenmg 28 Vin the wall thereof.

'With the several parts as shown, the reversing valve 58 will be inposition to effect communication'between ports 50 and 53, and the port51 will be uncovered. As the port 50 is in communication with the righthand end of the cylinder by means of passage 48, space 47, and passage46, and as the port 53 communicates through passages 54 and 56 with thechamber 5 which is under the inluence of the vacuum, it is evident thatthe right hand end of the cylinder will be subjected to the vacuum whileits opposite end is subjected to atmospheric pressure entering throughthe uncovered port V51, as a result of which, the piston 34 will movetoward the right. As the piston travels in this drection the valve 35will be moved to uncover port 21 and to connect port 22 with port 23,thus reversing the conditions within the spaces formed between the outercasings and the inflations of the two sets of teat cups, and causingatmospheric pressure to be appliedwith respect to the teat cupsconnected to the .left hand set of nipples,

Lacasse Awhile the teat cups connected to the right hand set of nippleswill be subjected to the vacuum. It w11 thus be seen that the spacesbetween the casings and the inflations of the teat cups will bealternately subjected to vacuum and atmospheric pressure as the pist tonreclprocates, whereby the milking operation will be carried on 1n themanner above i set f orth. As the piston 34 moves from left .to rlghtthe reversing valve 58 will be carried with it, but the valve will notshift its positlon wlth respect to the piston until the peak of itswedge-shaped portion has passed the peak of the wedge-shaped head 63 ofthe plunger 64, as above explained, and yat this instant the valve58will be shifted quickly upon its seat to its other operative position,in Whlch the ports'i53 and 51 will be placed 1ncommunication with oneanother and the port 50 will be uncovered. With the parts in thisposition the left end of the cylmder will be subjected to vacuum and theright end will be subjected to the atmosphere, thereby causing thepiston to move in the opposite direction until the reversing valve isagain shifted upon its seat, and the above described operations repeatedas long as the apparatus is being used.

The speed of travel of the piston 34 may be varied by means of theadjustable valve 57 which is adapted to vary the effective cross-sectionof the passage 56 extending between the passage 54 and the chamber 5.

From the above description it will be evii dent that I have provided apulsator mechamsm which possesses the following advantages. It 1s simplein its construction, positive in'its operation and not liable to get outof y"order, and inexpensive to manufacture. Moreover., the apparatus 1seiiicient and economical in operation, and is capable of being operatedby unskilled persons by reason of the simplicity of the operationthereof. As the piston is maintained firmly upon its valve seat in thecylinder by its own weight and by the pressure of the atmosphere uponits upper portion, asabove pointed out, and as the self-aligning ends ofthe cylinder move downward with the piston as wear occurs between it andthe valve seat, there can be no leakage between these several parts.Furthermore, no leakage can occur between the reversing valve and itsseat, as the valve is pressed upon its. seat by its own weight, byatmospheric pressure and by the spring pressed plunger which controlsits movement. It will thus be seen that all of the forces acting uponthe `piston arid the reversing valve tend to maintain them on theirrespective seats irrespective of any wear which may take place.Furthermore, the several parts of the apparatus may be assembled withthe minimum `expenditure of time and of labor, thus lessening the costof production. When it is necessary 'or desirableto repair or clean thefrom the body portion 18 of the cylinder.'

Referring to Figures '14, 15 4and .16, the pulsator mechanism is shownasl comprising a casting 71 removably supported upon the cover or lid 72of the milk pail and normally maintained in position thereon by itsWeight, and when the apparatus 1s 1n use bythe suction within the Pa1l.This construction permits of the removal of the pulsator mechanismfromthe cover, whereby the latter may be more easily handled when it isdesired to clean the same, and furthermore, it permits the cover to beimmersed in the cleaning fluid without subJectingthe pulsator thereto.The casting 71 is provided with a downwardly-extending projection 73through which the port 7 extends, and which, when the casting 'is inpositlon, extends through a bushing 74 secured to the cover 72. In orderto form an 'air-tight. joint between the casting and the cover asuitable packing 75 is interposed between" the upper end of the bushingand the bottom of the casting. The upper end of the bushing and thelower surface of the packing are preferably beveled, as shown, wherebyto form a more perfect air-tight joint between the parts. The removableendy portions 19 and 20 of the cylinder 18 are prevented from beingdisplaced by the casings of the milk cocks 76 and 77 which arepreferably formed integral with the cover 72 and positioned adjacent theopposite ends of the pulsator cylinder. The milk cocks control the flowof milk through the milk nipples 78 and 79.

The pulsator mechanism which is of the same construction as thathereinabove described in connection with Figures 1 to 13, inclusive, isshown as being adapted to be used in connect-ion with teat cup clustersof that type having four teat cups arranged in pairs to which pairs thesuction is alternately applied. In order to adapt the ap- -paratus to beused with teat cup clusters of this type the ports 21 and 23 areprovided with branches which communicate, respectively, with a pair ofnipples 80 and 81, and with a pair of nipples 82 and 83. The nipples 78,81 and 83 are adapted to be connected to one teat cup cluster, and thenipples 79, 80 and 82 are adapted to be connected to .another teat cupcluster. But one teat cup cluster is illustrated, and, as shown, theinflations ofthe teat cups communicate with the manifold 84 which isconnected by flexible tubing to the nip le 78 of the milk cock 76, andthe space between the outer casing and the infiation of the pairs ofteat cups 85 and 86 are connected respectively to the manifolds 87 and88, which in turn are connected by flexible tubing to the nipples 81 and83. In operation the milk cock 76 controlling the nipple 78 is openedwhereby the inflations of all of the teat cups are continuouslysubjected to the vacuum within the pail, and the pairs of teat cups 85and 86 are alternately subjectedoto vacuum and atmospheric pressure 1nthe usual manner. The nipples 79, 80 and 82 are similarly connected toanother teat cup cluster, not shown. The opening 38 of the cylinder 18is shown `as being provided with an air filter 89 comprising wirenetting or the like, faced on both sides by a suitable filtering fabric.

The outer end of the nipple 3, which is connected to thel source ofvacuum, extends through a circular opening 90 formed in an angularmember 91l secured to the cover 72. The opening, which is concentricwith the nipple, receives the end of the flexible tubing or hose 92secured thereto and serves to assist in preventing accidentaldisplacement of the casting 71 Awith respect to the cover 72. To furtherassist in preventing accidental displacement of the casting 71, a curvedplate 93 is secured to the upper surface of the coverin position to liebelow the nipples 80, 81, 82 and 83. when the casting is in place. Theplate is provided at its end with upwardly extending portions 94 spacedlaterally from the outer nipples 8O and 83 a sufiicient distance topermit of the flexible tubing being attached thereto. yAt their upperends the upstanding portions 94 are provided with inwardly extendingportions 95 which will overlie the flexible tubing upon the nipples 80and 83, but which will not overlie the nipples, whereby, when theflexible tubing is removed lfrom the nipples, they will pass freelybetween the inwardly extending portions 95 when the casting 72 is raisedfrom the cover. When the flexible tubing is secured to the nipples 80and 83 the inwardly extending portions 95, which overlie the tubing atthe outer side of the nipples, will prevent the casting from beingraised, and the upstanding portions 94 will prevent lateral movement ofthe casting. The cover is provided with a handle 96 which is seclred tothe casings of the milk cocks 76 and 77. I

To remove the pulsator mechanism it is merely necessary to detach thehose 92 from the nipple 3 and the flexible tubing from the nipplesl 80,81, 82 and 83, and then to raise the casting 71 from the cover and carryit forwardly, the front portion of the mechanism being tilted upwardlyslightly to permit. the nipple 3 to be freely withdrawn from itsposition within the opening in the angular member 91. After the pulsatormechanism has been removed, the cover '72 manner hereinabove describedin connection in whatever form its with its removal therefrom.

WhileI have'illustrated and described in detail two preferred forms andapplications ofv my invention, it will be understood that the inventionmay beA modifiedv in various ways and I do not therefore wish to .belimited to the particular constructions shown, but intend to cover myinvention broadly principles may be embodied. f

Having thus described my invention,- what I claim as 'new and desire tosecure by Letters Patent'isz- 1. In pulsator mechanism for milking apparatus, a cylinder, a piston mounted to reciprocate therein and havingannular grooves formed in its outer surface adjacent its ends, washerscarried, by said piston adjacent the' ends thereof and extendingAbetween said piston and the wall of said cylinder and in register withsaid grooves and split rings of yieldin material mounted within saidgrooves for olding said washers in engagement with said cylinder wall,said rings havin their ends abutting and having internal iametersgreater than the internal diameters of the grooves whereby to permitbodily movement of said rings with respect to said grooves.

2. In pulsatorsmechanism for milkin apparatus, a cylinder, a'vacuumoperate piston mounted to reciprocate therein, a reversing valve carriedby said iston and movable with respect thereto, sai valve being providedwith a wedge shaped projection, and a yielding member havin a wedge shad portionengaging the we ge shaped projection of said valve to controlthe movement of this valve and force it against its seat. 3. In pulsatormechanism for milln'ng apparatus, a cylinder comprising a centralportion and removable end portions,and a piston mounted to reciprocatewithin said cylinder and serving to hold said end portions in position.

4. In pulsator mechanism for milking apparatus, a cylinder comprising acentral portion and removable endv` portions engaging the end walls ofsaid central portion `and a piston mounted to reciprocate within saidcylinder and serving to hold said end portions in place.

5. In pulsator mechanism for milkingA apparatus, a cylinder comprising acentral portion and removable cap-shaped end portions having their innerends engaging said central portion, and a piston mounted to 4centrictherewith.

reciprocate within said cylinder and serving to hold-said end portionsin place.

6. In pulsator mechanism formilking ap` paratus, a cylinder comprising acentral ortion and removable ca -shaped end portions having their inneren s abutting against the. end walls of said central portion and a pis-'ton mounted to reciprocate within said cyl- -tion being provided with avalve seat havin" 'ports formed therein, and a iston mount toreciprocate within said cy inder and provided with a valve coacting withsaid ports, said piston being held in pressln engagement with said valveseat the en portions of said cylinder bein poiiy movaba with respect tothe centra portion thereof, and being held in place by said piston,whereby they will move rwith said piston as the latter is moved to takeup wear between the same and said valve seat.

`8. In pulsator mechanism for milking apparatus, a cylinder comprising-acentral portion and end portions bodily movable with respect to saidcentral portion and engaging the end walls thereof, said central portionhaving a valve seat in the lower portion thereof provided with ports,and a piston mounted to reciprocateVwit-hin said cylinder and serving tohold the end portions thereof in place, said piston being provided inits lower portion with a valve coacting with said ports and being heldin pressing engagement with said valve seat whereb as wear occursbetween said valve, seat an said piston the Ilatter will be moved towardthe valve seat and the end portions of said cylinderv will move withsaid piston and remain con- 9. In pulsator mechanism for milkingapparatus, a cylinder, a vacuum operated piston mounted to reciprocatethereln, a reversing valve carried by said piston and movable withrespect'thereto, and means adaptedto maintain said valve in one of itsoperative positions during a predetermined portionF of the travel ofsaid piston and then to move said valve to occupy the other of itspositions, said means serving to press said valve in engagement with Isaid 'piston whereby leakage due to wear is prevented. Y i

10. In pulsator mechanism for milking apparatus, a cylinder havinan'opening in its top, a vacuum operate piston mounted to reciprocatetherein, a reversing valve carried by said piston and movable withrespect thereto, a plug removably supportedinthe opening in saidcylinder, and reciprocating means carried' hy said plug to control themovement of said valve. l

11. In pulsator mechanism for milking aplll paratus, a cylinder havin anopening in its top, a vacuum operate( piston mounted to reciprocatetherein, a reversing valve carried by said piston and movable withrespect thereto, a plug removably supported in the opening in saidcylinder and provided with guide Ways, and means carried by said plug tocontrol the movement of said valve, said means being provided withrollers engaging said guideways.

12. In pulsator mechanism for milking apparatus, a cylinder, a vacuumoperated piston mounted to reciprocate therein, a reversing valvecarried by said piston and movable with respect thereto, and meansreciprocating in a line at right angles to the line of travel of saidvalve to control the movement thereof.

13. In apparatus of the character described, a milk receptacle. having aduct adapted to be connected to a source ot vacuum, a valve for openingand closing said duct, a chamber for said valve having an open end, thewall of said chamber adjacent its open end being beveled to forni aseat, and a closure for said chamber having a beveled surface engagingsaid seat to form a Huid-tight joint therewith.

14. In apparat-us of the character described, a milk receptacle having aduet adapted to be connected to a source of vacuum, a valve for openingand closing said duct, and a chamber Withln which said valve is mountedto reciprocate, the outer end of said valve being provided with a groovewhereby it may be gripped by the fingers and withdrawn from said chamber15. In pulsator mechanism for milking apparatus, a cylinder including afixed portion and a portion capable of lateral movement with respectthereto, and a piston mounted to reciprocate Within said cylinder.

16. In pulsator mechanism for milking apparatus, a cylinder including afixed portion and an adjustable portion` said fixed portionbeing'provided with a valve seat. and a piston mounted to reciprocatewithin said cylindcr and pressed against said valve seat, said pistonengaging said adjustable portion of said cylinder, whereby as wearoccurs between said piston and said valve seat said adjustable portionof said cylinder will be moved relatively to the fixed portion thereofby the movement of said piston towards said valve scat.

17. In pulsator mechanism for milking apparatus, a cylinder including afixed portion and a self-aligning portion, and a piston mounted toreciprocate within said 4cylinder and engaging said portions thereo't'.

1S. In apparatus of the kind described, areeeptacle cover, pulsatormechanism removably supported thereon including nipples provided withcircumferentially extend` ing enlarged portions, retaining means carriedby the cover and provided with apertures of sutiicient diameter topermit passage therethrough of the enlarged portions of the nipples. andflexible tubing detachably connected to the nipples and surrounding theenlarged portions thereof, said tubing being normally small enough topass freely through the apertures of the retainingmeans, but beingexpanded by the cnlargcd portions of the nipples suliciently to preventthe withdrawal of the nipples and the surrounding tubing through theapertures.

19. In a milking machine pulsator, in combination, a pulsator body, apiston slidable thereon and a cylinder head supported by the piston andi'ree to more with the piston in a direction t 'ausverse to the normalpath of piston travel.

In testimony whereof I have ailixed my signature to this specification.

HERBERT MCCORNACK.

